it is a huge cylinder, but the set up is the reverse of your usual cylinder tanks, instead of the coil heating the water - the water heats the coil.

We have mains cold water going into the coil, and the tank is full of stored hot water,,, this heats the cold water and becomes hot water.

The main advantage is it is a better way of having mixed heat sources - so we have several coils.

we ultimately intend to have the wood fired rayburn (or esse or similar), solar tubes, and efficient gas boiler all connected the same system. The gas boiler was possibly overkill, but I'm making allowances for illness etc (we do have a disabled member of the family). When hot water is needed, the boiler will only add more heat to the system if it needs topping up after the rayburn and solar tubes. Hopefully, between the tubes and rayburn we will do fine.

other advantages are the hot water is mains pressure and potable, and if we put the heating on,there is a big store of hot water, so the house becomes warm straight away.

Red

I like like minded people... a bit like minded anyway.. well people with bits of their minds that are like the bits of my mind that I like...

Red, I'm intrigued, it seems somewhat counter intuitive, can you give more details, what is the size of the store, temperature, length of the mains coil, and output temperature (and how is this controlled). You seem to imply the store will also provide space heating, how does that work? Sorry to be so inquisitive but it all sounds very interesting.

What we have is a huge tank of water (just over 300Ltr). Think of it as a heat battery, we can put heat in from different sources and take heat out either as hot water to the taps or as heat to the radiators.

Heat goes in from

Rayburn: this is directly connected to the tank and water circulates via gravity.

Solar panels: there is a coil in the bottom of the tank (not connected yet).

Gas Boiler: There is a separate coil in the middle of the tank for this. Advantage of this is that the boiler has a small circuit of water, it gets up to efficient temp quickly and doesn’t have all the sludge from radiators pumped through it, so should enhance its life a bit.

(We also put an electric immersion in - but this is just for total emergencies - we just thought we would put it in whilst we were at it - sort of future proofing cover all bases.)

Heat out:

Heating, the water in the tank is pumped round the radiators, the pipes however are 1/3 and 2/3 of the way up the tank, so the heating never steals all the hot water from the domestic hot water system.

Hot water: a large coil in the tank takes in cold mains at the bottom and heats it as it runs through the coil coming out hot at the top. Then a thermostatic mixing valve (TMV) blends the super hot water with more cold water to provide a constant supply of non-scalding water.

Hopefully in the summer the water will be heated by solar, in spring and autumn there will still be some solar gain. We can heat using gas if we need to or if we are good and keep the Rayburn loaded with wood then we won’t need the gas boiler to work run at all.

Red

I like like minded people... a bit like minded anyway.. well people with bits of their minds that are like the bits of my mind that I like...

ooh that sounds perfect for what I want, I have a rayburn and a front room fire with a back boiler and a redundant oil boiler, currently the rayburn and the front room fire heat the two rooms beautifully but am unable to pump the resulting hot water through the radiators hence it boils the header tank in the attic....my wish would be to be able to put the heating system back to how it was, prior to the installation of the oil bolier the house was heated perfectly well...I would also wish to add in solar tubes as you have done..tis my plan anyway. Finding a heating engineer that can help me has been very hard and I have had no success as yet, am still saving furiously though as sure it will be expensive. Can anyone recommend a suitable engineer??

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